Patent GB-885907-A (GB)
Title: An instrument for indicating slip, differences in speed, or the like
Inventor: BARR ALBERT EDWARD DE
IPC: G01P3/08
Filed: 1957-01-25
Abstract: 885,907. Indicating relative speeds of textile drafting rollers. BRITISH COTTON INDUSTRY RESEARCH ASSOCIATION. April 17, 1958 [Jan. 25, 1957], No. 2711/57. Class 120(3) [Also in Group XIX] An instrument for measuring slip, differences in speed and the like comprises a differential mechanism having two driving elements and a follower, means associated with the follower adapted to indicate its movement visually, and a pointer or the like adapted to be driven from the follower during a predetermined number of rotations of one of the driving elements so as to indicate the magnitude of any difference in speed of the two driving elements. Members such as two drafting rollers, the difference in speed or slip between which is to be indicated, are each brought into frictional driving contact with rubber-faced rollers 23 mounted on shafts 21 rotatable in sleeves 15, 16 in opposite ends of a fixed shaft sheath 14. The shafts carry long toothed wheels 25, 26 and are adjustable axially by means of screws 27, 28 and slots 29, 30 in the sheath. A differential gear 42 comprises input shafts 41, 43 driven in opposite directions by the wheels 25, 26 through gear trains including gear wheels 36, 37 which project through slots 38, 39 in the sheath and 90 degrees cut-outs in the sleeves 15, 16. The output of the differential gear comprises a pinion cage 50 which rotates at a speed equal to the difference in speed between the shafts 41, 43 and is connected positively through gears 53, 54, 61, 62, 64, 65 with an indicator disc visible through a window 70 and having circumferential markings. Movement of the disc indicates speed difference. The gear wheel 61 is rotatable about a spindle carrying a pointer and carrying a friction clutch disc 86. A rod 74 is carried on levers 71, 73 pivoted on the shafts 41, 43, and the other end of the lever 71 is connected by a rod 75 to a knob 76. The rod 74 is connected by a link to a lever 81 carrying pegs 83 engaging a groove 84 in the clutch knob 85. A spring 77 normally holds the parts with the clutch open but when the knob 76 is pressed, the disc 86 is pressed against the wheel 61 so that the pointer is moved over a dial according to the speed difference. When the knob 76 is pressed, it also causes a pinion 102 driven from the shaft 41 to engage a pinion 92 and rotate a shaft 91 carrying a worm 93 engaging a worm-wheel 94 rotatable on a shaft 95, and at the same time a pin 103 is swung out of a notch 105 in a disc 99 fast on the shaft 95 to allow the latter to rotate, the worm-wheel 94 and disc 99 being urged together by a spring 96. When the knob 76 is released, the clutch 81, 61 is held closed by the pin 103 riding on the disc 99, until, when the shaft 41 and its actuating roller have made ten revolutions, the notch 105 moves into alignment with the pin and the pointer is disconnected, its position indicating the speed difference over a period of ten revolutions of one of the members. To reset the pointer, a knob 118 is pressed, and through an over-centre spring 115, plate 112, pin 114, rod 109, rod 106 and lever 107, a pointed tip of the lever 107 is moved against a cusp-shaped cam 88 on the pointer spindle to move the latter to its original position.